35 lines
1.3 KiB
Plaintext
35 lines
1.3 KiB
Plaintext
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Freescale mx25 TS conversion queue module
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mx25 touchscreen conversion queue module which controls the ADC unit of the
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mx25 for attached touchscreens.
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Required properties:
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- compatible: Should be "fsl,imx25-tcq".
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- reg: Memory range of the device.
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- interrupts: Should be the interrupt number associated with this module within
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the tscadc unit (<0>).
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- fsl,wires: Should be '<4>' or '<5>'
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Optional properties:
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- fsl,pen-debounce-ns: Pen debounce time in nanoseconds.
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- fsl,pen-threshold: Pen-down threshold for the touchscreen. This is a value
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between 1 and 4096. It is the ratio between the internal reference voltage
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and the measured voltage after the plate was precharged. Resistance between
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plates and therefore the voltage decreases with pressure so that a smaller
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value is equivalent to a higher pressure.
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- fsl,settling-time-ns: Settling time in nanoseconds. The settling time is before
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the actual touch detection to wait for an even charge distribution in the
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plate.
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This device includes two conversion queues which can be added as subnodes.
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The first queue is for the touchscreen, the second for general purpose ADC.
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Example:
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tsc: tcq@50030400 {
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compatible = "fsl,imx25-tcq";
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reg = <0x50030400 0x60>;
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interrupt-parent = <&tscadc>;
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interrupts = <0>;
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fsl,wires = <4>;
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};
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